ABSTRACT
Dissipative solitons, which result from the intricate balance between dispersion and nonlinearity as well as gain and loss, are of the fundamental scientific interest and numerous important applications. Here, we report a fiber laser that generates bisoliton - two consecutive dissipative solitons that preserve a fixed separation between them. Deviations from this separation result in its restoration. It is also found that these bisolitons have multiple discrete equilibrium distances with the quantized separations, as is confirmed by the theoretical analysis and the experimental observations. The main feature of our laser is the anomalous dispersion that is increased by an order of magnitude in comparison to previous studies. Then the spectral filtering effect plays a significant role in pulse-shaping. The proposed laser has the potential applications in optical communications and high-resolution optics for coding and transmission of information in higher-level modulation formats.
ABSTRACT
Hepatitis B virus (HBV) DNA polymerase transactivated protein 1 (HBVDNAPTP1) is a novel protein upregulated by HBV DNA polymerase, which has been screened by suppression subtractive hybridization technique (SSH) (GenBank Acc. No. AY450389). A vector pcDNA3.1 (-)/myc-His A-HBVDNAPTP1 was constructed and used to transfect acute monocytic leukemia cell line THP-1. HBVDNAPTP1 expression was detected by Western blot analysis in the cells. A cDNA library of genes downregulated by HBVDNAPTP1 in THP-1 cells was made in pGEM-T Easy using SSH. The cDNAs were sequenced and analyzed with BLAST search against the sequences in GenBank. Some sequences, such as DNA repair protein SWI5 homolog (SWI5) and CTS telomere maintenance complex component 1 (CTC1), might be involved in DNA repair. Protein expression of SWI5 and CTC1 was identified by Western blot in THP-1 cells. HBVDNAPTP1 could downregulate the expression of SWI5 and CTC1 at translation level.
Subject(s)
DNA Repair , Hepatitis B virus/metabolism , Hepatitis B/genetics , Host-Pathogen Interactions , Nuclear Proteins/genetics , Telomere-Binding Proteins/genetics , Viral Proteins/metabolism , Down-Regulation , Hepatitis B/metabolism , Hepatitis B virus/genetics , Humans , Nuclear Proteins/metabolism , Telomere-Binding Proteins/metabolism , Viral Proteins/geneticsABSTRACT
Graphene, whose absorbance is approximately independent of wavelength, allows broadband light-matter interactions with ultrafast responses. The interband optical absorption of graphene can be saturated readily under strong excitation, thereby enabling scientists to exploit the photonic properties of graphene to realize ultrafast lasers. The evanescent field interaction scheme of the propagating light with graphene covered on a D-shaped fibre or microfibre has been employed extensively because of the nonblocking configuration. Obviously, most of the fibre surface is unused in these techniques. Here, we exploit a graphene-clad microfibre (GCM) saturable absorber in a mode-locked fibre laser for the generation of ultrafast pulses. The proposed all-surface technique can guarantee a higher efficiency of light-graphene interactions than the aforementioned techniques. Our GCM-based saturable absorber can generate ultrafast optical pulses within 1.5 µm. This saturable absorber is compatible with current fibre lasers and has many merits such as low saturation intensities, ultrafast recovery times, and wide wavelength ranges. The proposed saturable absorber will pave the way for graphene-based wideband photonics.
ABSTRACT
Fibraurin, chasmanthin, and palmarin were isolated from the stems of FIBRAUREA CHLOROLEUCA, Fam. Menispermaceae. The structure of the minor constituent, palmarin, was determined by X-ray crystallographic analysis.
